reported the polyubiquitylation of multiple Lys residue of tau‐AC in the human AD brain.[5d] Because polyubiquitin chains can stabilize β‐strand stacking, we postulated that tau‐AC ubiquitylation, unlike phosphorylation, will further facilitate polymeric tau‐AC formation.[3] However, the mechanistic link between tau cleavage and its effect on PTM events (or vice versa) during the course of tauopathies remains to be determined. Here, MAPT is linked to tauopathy.